Numerical investigation of heat transfer in impinging axial and radial jets with superimposed swirl

The effect of inflow conditions on the development of non-swirling versus swirling impinging turbulent jets

“…In the context of modelling, the use of aerodynamically induced swirl means avoiding having to account for vane (or insert) induced flow behaviour at the exit plane. Moreover, the literature in this area also appears to indicate some contradictory results as to whether swirl positively [31,36,39,41] or negatively [42,43] affects heat transfer at the impingement surface, as well as the significance of this impact. This is due to the multitude of geometric generators used.…”

“…Whilst Ichimiya and Tsukamoto [45] also studied a swirling impinging jet with aerodynamically generated swirl at Re = 11,500, the swirl intensity was simplistically characterized by the angle of tangential flow entry in their setup which makes it difficult to relate their outcomes in the context of the wider body of swirl research. By reviewing most of the literature published to date, it is evident that prior research into swirling impinging jets (either aerodynamically or geometrically generated) focussed on studying the effects of swirl intensity on heat transfer, with little attention to the effects of upstream (inflow) conditions on jet development, which may explain why different studies have reported varied outcomes on the relationship between surface heat transfer and the introduction of swirl [31,34,36,[41][42][43].…”

Experimental study of an impinging jet with different swirl rates

“…Some of the authors report a decrease of the transfer coefficients compared to the non-swirling impinging jet flow (Owsenek et al, 1997;Huang and El-Genk, 1998). Azevedo et al (1997) applied the naphthalene sublimation technique to study the influence of flow parameters on the mass transfer coefficients and determined their overall decrease in the swirling impinging jet for Re = 9000-45,000, H/D = 2-8 and S = 0-0.74.…”

Heat Transfer Characteristics of Swirling Impinging Jets

“…This allowed for the swirling effect of the flow to develop. This aspect of a separation between the swirl generator and the nozzle exit was also incorporated into the experiments of Alekseenko et al [5] for analysing the flow using two-dimensional particle image velocimetry, Numerical models of the effects of imposing swirl on axial and radial jets were discussed by Owsenek et al [6]. In this study it was observed that the axially swirling jet significantly reduced the heat transfer of the impingement surface for H/D=1.25 and for Reynolds numbers below and including 1000.…”